Dielectrophoresis of DNA: Quantification by impedance measurements

Dielectrophoretic properties of DNA have been determined by measuring capacitance changes between planar microelectrodes. DNA sizes ranged from 100 bp to 48 kbp, DNA concentrations from below 0.1 to 70 μg∕ml. Dielectrophoretic spectra exhibited maximum response around 3 kHz and 3 MHz. The strongest response was found for very long DNA (above 10 kbp) and for short 100 bp fragments, which corresponds to the persistence length of DNA. The method allows for an uncomplicated, automatic acquisition of the dielectrophoretic properties of submicroscopical objects without the need for labeling protocols or optical accessibility.     

Interaction between cells in dielectrophoresis and electrorotation experiments

Progress in microelectrode-based technologies has facilitated the development of sophisticated methods for manipulating and separating cells, bacteria, and other bioparticles. For many of these various applications, the theoretical modeling of the electrical response of compartmentalized particles to an external field is important. In this paper we address the analysis of the interaction between cells immersed in rf fields. We use an integral formulation of the problem derived from a consideration of the charge densities induced at the interfaces of the particle compartments. The numerical solution by a boundary element technique allows characterization of their dielectric properties. Experimental validation of this theoretical model is obtained by investigating two effects: (1) The influence that dipolar “pearl chaining” has on the dielectrophoretic behavior of human T lymphocytes and (2) the frequency variation of the spin and orbital torques of approaching insulinoma β-cells in a rotating field.     

A simplified design of the staggered herringbone micromixer for practical applications

We demonstrated a simple method for the device design of a staggered herringbone micromixer (SHM) using numerical simulation. By correlating the simulated concentrations with channel length, we obtained a series of concentration versus channel length profiles, and used mixing completion length L_m as the only parameter to evaluate the performance of device structure on mixing. Fluorescence quenching experiments were subsequently conducted to verify the optimized SHM structure for a specific application. Good agreement was found between the optimization and the experimental data. Since L_m is straightforward, easily defined and calculated parameter for characterization of mixing performance, this method for designing micromixers is simple and effective for practical applications.     

福建省体育本科院系龙狮运动的开展现状与对策

文章采用文献资料法、问卷调查法、访谈法和数理统计法等研究方法,对福建省体育本科院系龙狮运动开展状况进行了调研。研究认为,福建省体育本科院系龙狮运动的开展效果良好,深受学生的喜爱,发展前景广阔。加强专业师资的引进与培训,提高训练的专业性,加大投入、鼓励龙狮队走出校门以及加大宣传普及力度是提升福建省体育本科院系龙狮运动发展的途径。     

篮球运动中的常见损伤分析

篮球运动产生的初期,是没有任何身体接触的,而且也是禁止身体接触的。但随着篮球运动的发展,观众要求的提高,比赛竞争性、对抗性的日益激烈,篮球比赛规则从身体不接触过渡到身体可以接触,进而成为了身体直接对抗。随之而来的就是比赛和训练中出现的各种运动损伤也不断增多。文章通过对日常和比赛中产生运动损伤进行分析,以加强防范措施,最大限度地减少或避免损伤,从而保证篮球的训练与教学的正常进行。     

竞赛法在体育教学中的应用——以篮球课教学为例

文章主要根据篮球运动的对抗性、竞争激烈的特点,提出在篮球课教学中应用竞赛的方法和手段,传授篮球运动的基本知识、技术及技能,使学生们在学习过程中能更进一步了解篮球运动的起源与发展状况,培养学生们的学习情趣,调动学生学习的积极性与与自觉性,通过篮球技战术的竞赛法教学,在相互的角逐与对抗中,培养学生们的竞争意识与竞争能力,启发和调动学生们勇于开拓,不断进取的精神和优秀的品质素质,起到积极作用。     

厦门市中小学校体育设施向社区开放的现状调查

调查厦门市中小学校体育设施向社区开放的现状以及厦门市民的认知、态度;70%的中小学校体育设施向社区开放或曾经开放过。影响学校体育设施向社区开放的主要因素为：缺乏管理力量和经费、学校与社区在开放中的责权不明、学校的安全问题等,由此提出＂政府协调,社区负责,学校辅助,适度有偿＂的建议。     

项目组合条件下项目规模决策的生态学思维研究

文章首先分析了企业规模和项目规模的含义,发现两者在性态、制约因素等方面存在着较大差异.然后分析了企业规模决策方法在项目组合条件下项目规模决策中的适用性,发现前者不能很好满足后者的需要.从生态学与管理学的交叉研究成果得到启示,提出了项目组合条件下项目规模决策的生态学思维,并就项目的生命体属性、项目类似于种群的属性、项目组合类似于群落的生态学属性三个方面对这种思维的可行性作了论证.     

江西矿山公园建设与废弃矿山开发研究

本文通过回顾矿业旅游开发的相关理论与实践,结合江西省矿山关闭和后续利用的现实状况,指出江西省目前仍缺乏对矿业文化挖掘和矿山公园建设的重视,并从矿山环境治理和矿业城镇经济转型方面提出了江西省建设矿山公园和加强对废弃矿山开发研究的观点。     

Subordination and superordination properties of multivalent functions defined by certain integral operator

For normalized multivalent functions, we study different applications of the theory of differential subordination and superordination, that are connected to a recent linear operator defined by Liu and Owa.